Michel Deriaz

After an engineer degree in telecommunications and a master in computer science, Michel Deriaz did a PhD in economical and social sciences. He spent then three years in the industry before coming back at University as R&D Project Manager. Among his main realizations there are FoxyTag, a worldwide speed camera warning system with thousands of users, and FoxyTour, a museum and city guide that adapts automatically to the preferences of its user.

Born the 17th of April 1976, married, 3 children, Michel has spent all his live in Geneva. He likes different kinds of sports including diving, skiing or hiking, and is member of some professional associations like the CREG (Centre de Rencontre des Entrepreneurs - Genève). He used to finance his studies by working as a trainer for private institutions as well as for the police where he taught cryptology and computer security.

Abstract. Can we trust without any reliable truth information? Most trust architectures work in a similar way: a trustor makes some observations, rates the trustee, and makes recommendations to his friends. When he faces a new case, he checks his trust table and uses recommendations given by trustworthy friends to decide whether he will undertake a given action. But what if the observations that are used to update the trust tables are wrong? How to deal with what we call the “uncertainty of the truth”? This paper presents how people that publish and remove virtual tags are able to create trust relations between them. A simulator as well as a concrete and widely deployed application have been used to validate our model. We observed good and encouraging results in general, but also some weaknesses, brought out through specific scenarios.

Abstract. Current speed cameras alerting systems heavily rely on humans to check the trustworthiness of information sent by their users. Hence, these systems are often either expensive or suffer from drawbacks, such as incomplete information, for example, concerning mobile speed cameras. We propose an application called FoxyTag to address most of the previous issues by using a computational trust engine instead of human checks. FoxyTag lets any driver equipped with a Java/GPS enabled mobile phone post a virtual tag about a speed camera to notify other equipped drivers who can confirm or deny the (short-lived) presence of the (mobile) camera. The novel aspect of our trust engine is that it must be location and time aware to automatically compute the trustworthiness of the given tag. We have validated FoxyTag both in real-life settings and with a simulator for large-scale scenarios. The validation showed that our novel time-patterned trust metrics are appropriate.

Abstract. Spatial messaging is a term that defines the virtual publication of data in physical places. Generally, anyone in the neighborhood of such a publication point gets the message. Frameworks allowing the users to publish freely spatial messages already exist. However, the experiences realized with volunteers showed that there is only little interest in posting such notes. To our view, the main reason is that there are currently no trust and security mechanisms that inform about the trustworthiness of the messages, thus preventing any serious application. Filling this gap will promote the success of spatial messaging and the growing success of localization and mobile techniques will provide a good support for this concept. This paper describes the spatial messaging services that we are in the process to deploy with our new spatial messaging framework, which includes trust and security mechanisms.

Abstract. Decentralised systems made of autonomous devices and software are gaining more and more interest. These autonomous elements usually do not know each other in advance and act without any central control. They thus form a society of devices and software, and as such need: basic interaction mechanisms for understanding each other, and a social infrastructure supporting interactions taking place in an uncertain environment. In an effort to go beyond pre-established communication schema and to cope with uncertainty, this paper proposes an interaction mechanism based exclusively: on semantic information expressed using specifications, and on a social infrastructure relying on trust and reputation.

Abstract. This paper proposes the notion of Specification-Carrying Code as an interaction mechanism for self-assembly of autonomous decentralised software components. Each autonomous software entity incorporates more information than its operational behaviour, and publishes more data than its signature. The idea is to provide separately, for each entity, a functional part implementing its behaviour - the traditional program code; and an abstract description of the entity's functional behaviour and necessary parameters - a semantic behavioural description under the form of a formal specification. Interactions are exclusively based on the specifications and occur among entities with corresponding specifications. In the case of autonomic computing systems, in addition to functional aspects, the specification may carry a semantic description of non-functional information related to self-management. This paper presents the principles of the Specification-Carrying Code paradigm, the associated Service-Oriented Architecture, and it explains how self-managed systems can benefit from this paradigm.